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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

35984 results found.

  1. GRB 990123: Strong MeV CGRO-COMPTEL detection now posted on WWW
  2. "GRB 990123: New BV Observations"
  3. GRB 990123 Optical Follow-Up
  4. GRB 990123; Addendum to GCN 223
  5. GRB 990123: BATSE Observations
  6. GRB 990123 Keck Spectrum update
  7. GRB 990123 : Multiple and Distorted Images of the Host Galaxy?
  8. GRB990123 Optical Observations
  9. GRB 990123 Spectroscopic Redshifts
  10. GRB 990123: New Optical Observations, Decay Measure
  11. GRB 990123 Optical Follow-Up
  12. GRB 990123: Possible Gravitationally Lensed Burst?
  13. GRB 990123 optical observations
  14. GRB 990123: Pre-Burst Detection of an Apparent Host Galaxy
  15. GRB 990123 radio observations
  16. GRB 990123, new radio source
  17. GRB990123, Optical observation
  18. GRB 990123: Optical Decay Slope
  19. GRB 990123 r-band photometry
  20. GRB 990123 Optical Follow-up
  21. GRB990123, early optical counterpart detection
  22. GRB990123 Optical Observation
  23. GRB 990123: Bright New Source, Possible Optical Transient
  24. GRB 990123, Radio observations
  25. SN 1999E & GRB 980919
  26. Possible identification of SN1999E with GRB980910
  27. Optical Observations of GRB 981220
  28. GRB 981226: radio variable
  29. GRB981220
  30. GRB981220, Optical Observations
  31. GRB 981220 Optical observations
  32. GRB 981226 Optical Observations
  33. GRB 980613: Spectroscopy of the host galaxy
  34. GRB981226, sub-millimeter observations
  35. GRB981220, sub-millimeter observations
  36. GRB 981220 and GRB 981226, optical observations
  37. GRB 981226 radio observations
  38. GRB 981226
  39. GRB 981226 optical observations
  40. radio observations of GRB 981226
  41. GRB981220 B, R and I band observations
  42. GRB 981220:Optical Observations
  43. GRB 981220 optical R and I observations
  44. GRB981226, BeppoSAX Christmas GRB
  45. GRB 981226 - Infrared Observations
  46. GRB 981226 optical observations
  47. GRB 981220
  48. GRB 981220, radio observations
  49. GRB981226 Optical Observation
  50. GRB 981220, radio observations
  51. GRB 981220: BeppoSAX/GRBM results
  52. GRB981220 I-band Observations
  53. GRB 981220
  54. GRB 981220 Optical Observations
  55. GRB 981220, optical observations
  56. GRB 980326/Host Galaxy
  57. GRB981220 IPN error box
  58. GRB 981220: RXTE/ASM and BeppoSAX/GRBM results
  59. GRB980329 R,I flux calibration and R,I,K upper limits
  60. GRB980425: X-ray revised positions
  61. GRB 980923 BATSE Observations
  62. GRB980703 Very Long Baseline Interferometry
  63. GRB970508 optical observations
  64. GRB971214, association with a Galactic star?
  65. Optical Observations of the Host Galaxy of GRB 980519
  66. GRB980519, Optical Observations
  67. GRB980703, Host galaxy multicolor photometry
  68. GRB980703 - BeppoSAX/GRBM detection
  69. GRB 980703 (NFI observations)
  70. GRB980703 optical photometry
  71. GRB 980703: BATSE Observations
  72. GRB980703: Radio transient
  73. GRB980703 H-band Observations
  74. GRB 980703: Spectrum of the proposed optical counterpart
  75. RXTE Observation of GRB 980706
  76. GRB980703: Spectrum of the proposed optical counterpart
  77. GRB980703 Transient Optical Follow-Up
  78. GRB980703: LOTIS observation at early times
  79. GRB980613 Optical Observations
  80. GRB 980703
  81. GRB 980703 H-band Observations
  82. GRB980703 (optical R observations)
  83. GRB980706
  84. GRB980703: radio source/optical transient
  85. BeppoSAX NFI observations of GRB 980703
  86. GRB 980703: ASM Position & Intensity
  87. GRB980703
  88. GRB980703 optical followup
  89. GRB 980613 Near-IR observations
  90. GRB980613, optical observations
  91. GRB 980613: Optical transient and its host galaxy
  92. GRB 980613: Detection of the probable host galaxy
  93. GRB 980613: BATSE Observations
  94. GRB 980613 Optical Observations
  95. GRB 980613 optical observations
  96. GRB980613 Optical Observations
  97. GRB980613 observations from Palomar
  98. GRB980613 BeppoSAX-NFI follow up
  99. GRB 980613 new optical/IR observations
  100. GRB 980613 optical/IR obs.

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